As tire testing apparatuses, there are a tire uniformity measuring apparatus that measures the uniformity of a tire, and a tire balance measuring apparatus that measures the balance of a tire. In measurement using the tire testing apparatuses, a rim assembly to which a test tire is fixed has to be replaced for different tire based on bead diameter or bead breadth.
For example, in a tire testing apparatus disclosed in Patent Document 1, a cylindrical lower rim holder integrated with a lower rim is attached to a supporting member. A portion of an external surface of the supporting member forms an apparatus-side inclined surface that increases in diameter in a downward direction. On the other hand, since an external surface of the lower rim holder is also provided with a rim-side inclined surface that increases in diameter in the downward direction, the lower rim holder is supported by the supporting member by arranging the rim-side inclined surface on the apparatus-side inclined surface. By forming the apparatus-side inclined surface and the rim-side inclined surface, respectively, so as to increase in diameter in the downward direction, the apparatus-side inclined surface and the rim-side inclined surface can be brought into surface contact with each other, and the lower rim holder can be positioned on an axis of the apparatus-side inclined surface to stably support the lower rim holder.
An upper rim is arranged above the lower rim so as to face the lower rim. By moving the upper rim up and down by an air cylinder connected to the upper rim, the interval between the upper and lower rims can be adjusted based on the diameter or breadth of a tire.